In agriculture, a harvesting operation involves a harvester (i.e. the machine responsible for cutting the crop, but with no storage compartment or sometimes with a small buffer) and a hauler set comprising a towing vehicle which tows one or more crop trailers and moves side by side with the harvester such that a crop trailer receives the harvested crops. The hauler set is a specialized machine designed to be able to transit in the farm environment (e.g. mud, dust, ground holes, etc). After the hauler set is full, it drives to a place in the farm and unloads the crop into another type of trailer cart, which then can be hooked on a transporter (i.e. a vehicle which can run on a public road, highway or railway), composing a transporter set. The transporter set will deliver the harvested crop to a destination facility (i.e. a port, storage or any part of the infrastructure of a mill such as a barn, a silo, etc.).
In a different operation, the crop does not need to be transferred from trailer to trailer, since the crop trailer is used by both the hauler and the transporter. Instead, after the crop trailer is filled with crop, the crop trailer can be unhooked from the hauler (in particular and parked at the side of the cropping area) and (later) be hooked to the transporter. However, it is not unusual to have two kinds of trailers because a trailer for the cropping area may have any weight, height, width, and length, while a trailer towed on public roads must of course follow traffic laws and is hence designed with restrictions.
In a further operation, a hauler is not involved, but the crop trailer is towed by the transporter, which could both transit in public roads but also in the farm environment.
In the following description, for the sake of conciseness, it is mostly but not exclusively referred to the first case, i.e. to the provision of a hauler with hauler trailers (hauler set) for the cropping area and a transporter with crop trailers (transporter set) for the travel to the destination facility.
When the transporter set arrives at the destination facility, it navigates to a scale such that the crop load can be weighted. In some cases, a destination facility receives crops from different sources (from different farms and from different growers) and it is therefore important to securely define the source of the load (e.g. for a grower payment, or for operator or machine performance analysis). All these three involved vehicles (harvester, hauler, and transporter) have an on-board computer which is a device for machine interaction and data logging, including GNSS positioning.
During the time the hauler set drives side by side with the harvester, the on-board computer of each of these two machines are wirelessly connected, so the harvester can transmit to the hauler information related to the crop being loaded to it (e.g. farm site, farm plot, harvester engine data, positioning, etc).
During the time the hauler set is side by side with a transporter set for crop transferring, their on-board computers may also establish a wireless connection and the hauler on-board computer may transmit its own haul data but also the harvest data it had received from the harvester to the transporter on-board computer.
However, if the transporter is not present at the cropping area, but only the crop trailer of the transporter set, then there is no way the hauler on-board computer can communicate with the transporter on-board computer for transmitting the above mentioned data. Accordingly, it is common that there is more than one crop trailer per transporter, the crop trailers are left alone aside of the cropping area, waiting for a hauler set to load it (when the trailer is still empty), or waiting until a transporter arrives later to hook it and transport it to the destination facility (when the trailer is full already).